1. Field of the Invention
The present invention relates generally to devices and methods for percutaneous sealing of puncture sites in body lumens or tissue tracts. More specifically, the present invention relates to drug eluting vascular closure devices and methods for hemostasis of vascular puncture sites.
Percutaneous access of blood vessels in the human body is routinely performed for diagnostics or interventional procedures such as coronary and peripheral angiography, angioplasty, atherectomies, placement of vascular stents, coronary retroperfusion and retroinfusion, cerebral angiograms, treatment of strokes, cerebral aneurysms, and the like. Patients undergoing these procedures are often treated with anti-coagulants such as heparin, thrombolytics, and the like, which make the closure and hemostasis process of the puncture site in the vessel wall at the completion of such interventional procedures more difficult to achieve.
Various devices have been introduced to provide hemostasis, however none have been entirely successful. Some devices utilize collagen or other biological plugs to seal the puncture site. Alternatively, sutures and/or staples have also been applied to close the puncture site. External foreign objects such as plugs, sutures, or staples however may cause tissue reaction, inflammation, and/or infection as they all “leave something behind” to achieve hemostasis.
There is also another class of devices that use the body's own natural mechanism to achieve hemostasis wherein no foreign objects are left behind. Such devices typically provide hemostasis by sealing the puncture site from the inside of the vessel wall wherein the device is left in place in the vessel lumen until hemostasis is reached and thereafter removed. Although such safe and simple devices have achieved relative levels of success, they often can be slow in achieving complete hemostasis, particularly in highly anti-coagulated patients. Of particular interest to the present invention, examples of such devices are described in co-pending, commonly owned application Ser. No. 10/795,019 filed on Mar. 3, 2004; Ser. No. 10/821,633, filed on Apr. 9, 2004; Ser. No. 10/857,177, filed on May 27, 2004; and Ser. No. 10/974,008, filed on Oct. 25, 2004, the full disclosures of which are incorporated herein by reference.
There is yet another class of devices where highly thrombogenic substances are mixed and injected to the puncture site for the purpose of accelerating the hemostatic process. These mixtures contain one or more clot promoting substances, such as thrombin and/or fibrinogen, along with other substances, such as collagen. These devices generally work by first occluding the puncture site from the inside of the vessel, usually by use of a balloon, and then injecting the mixture into the tissue tract. The balloon is then removed. Such devices suffer from several drawbacks which may cause severe complications. For example, the occluding member may not be adequate to prevent these highly thrombogenic substances from entering the blood vessel. Further, the injection of the mixture is often not well controlled and highly technique dependant, which again may allow these substances to enter the blood stream.
In light of the above, it would be desirable to provide alternative devices and methods for providing complete hemostasis of a puncture site in a body lumen, particularly blood vessels of the human body. It would be particularly desirable if such devices and methods utilize the body's own natural healing mechanism to achieve hemostasis. It would be further desirable if the natural hemostatic process can be safely accelerated by the controlled use of chemical and/or biological agents. It would be further desirable if such devices and systems utilize a simple construction and user interface allowing for convenient application without numerous intermediary steps. Further, such devices should be safe and reliable without the need for much user intervention. At least some of these objective will be met by the devices and methods of the present invention described hereinafter.
2. Description of the Background Art
Hemostasis devices for use in blood vessels and tracts in the body are described in pending U.S. patent application Ser. Nos. 10/974,008; 10/857,177; 10/821,633; 10/795,019; and 10/718,504 and U.S. Pat. Nos. 6,656,207; 6,464,712; 6,056,770; 6,056,769; 6,045,570; 6,022,361; 5,951,589; 5,922,009; and 5,782,860, assigned to the assignee of the present application. The following U.S. Patents and Publications may be relevant to the present invention: U.S. Pat. Nos. 4,744,364; 4,852,568; 4,890,612; 5,108,421; 5,171,259; 5,258,000; 5,383,896; 5,419,765; 5,454,833; 5,626,601; 5,630,833; 5,634,936; 5,728,134; 5,836,913; 5,861,003; 5,868,778; 5,951,583; 5,957,952; 6,017,359; 6,048,358; and 6,296,657; U.S. Publication Nos. 2002/0133123; 2003/0055454; 2003/0045835; and 2004/0243052. The full disclosures of each of the above mentioned references are incorporated herein by reference.